Brent Cockbain has returned home to Wales for family reasons giving Cardiff Blues second row Deiniol Jones the opportunity to win only his third cap when he faces the 1995 World Champions.
The new Wales boss has shown faith in the 28-year-old lock who made his Wales debut under then coach Graham Henry against Samoa at Cardiff's Millennium Stadium in 2000 - Ruddock was Jones' club coach at Ebbw Vale at the time. His other cap was against Romania in Wrexham last November.
In the front row hooker Mefin Davies has recovered from the illness which kept him on the bench against the Pumas to replace Huw Bennett and Gethin Jenkins is preferred to Duncan Jones at loosehead prop.
"We are basically asking the side that performed so well against the Pumas last week to go out there and do it again," said Ruddock.
"We've had one or two injury worries but everyone has been patched up and come through okay to make themselves available.
"We are looking for a repeat performance against, what will be, a completely different prospect in terms of opposition. We know we will have to be at our very best in order to compete with the Springboks and we have a great opportunity here to test ourselves at the very highest level.
"We are a young side in terms of both age and experience, with the likes of Deiniol (Jones) coming into the set-up to win only his third cap.
"Mefin brings a little more experience to the front row at hooker, although Huw did not let anyone down with the way he played against Argentina. Gethin (Jenkins) has been given the chance to start in what is a tight selection call at loosehead prop.
"It is in matches like these that players get the chance to grow and to measure themselves against the very best and we are all very much looking forward to kick-off."
WALES: Gavin Henson (Ospreys); Hal Luscombe (Dragons), Sonny Parker (Ospreys), Tom Shanklin (Blues), Shane Williams (Ospreys); Nicky Robinson (Blues), Dwayne Peel (Scarlets); Gethin Jenkins (Blues), Mefin Davies (Unattached) Adam Jones (Ospreys), Deiniol Jones (Blues), Gareth Llewellyn (Unattached), Dafydd Jones (Scarlets), Colin Charvis (Newcastle Falcons, Captain), Michael Owen (Dragons).
REPLACEMENTS: Huw Bennett (Ospreys), Duncan Jones (Ospreys), Darren Morris (Leicester Tigers), Jonathan Thomas (Ospreys), Michael Phillips (Scarlets), Ceri Sweeney (Dragons), Rhys Williams (Blues)